This invention relates to light emitting blocks laid on side wall surfaces of garages, gardens and roads, or on wall surfaces of buildings and houses.
As one type of blocks laid on side wall surfaces provided for garages, gardens and roads, or on wall surfaces of buildings and houses, light collecting blocks are known, which are formed of transparent or translucent glass to take in sunlight from the ambient.
Conventionally, side wall surfaces of a garage or wall surfaces of a house have light collecting blocks arranged in positions where it is desired to take in sunlight from the ambient, and ordinary blocks arranged in other positions. During the daytime, ambient sunlight is allowed to pass through and taken in by the light collecting blocks to aid in illuminating the interior of the garage, building or house, to help in activities in the garage, building or house. However, during the nighttime, no sunlight is available from the ambient and the garage or house interior cannot be illuminated.
That is, the light collecting blocks as the conventional blocks are not effectively used when there is no sunlight from the ambient as at nighttime.
Having regard to the state of the art noted above, the object of this invention is to provide light emitting blocks excellent in response to emergency situations as well as workability, maintainability and design.
A light emitting block according to this invention is characterized by containing solar batteries arranged to receive sunlight penetrating a block surface portion to generate an electromotive force, an electric double layer capacitor for storing electric power generated by the solar batteries, a light emitting device disposed with a light emitting surface thereof opposed to a reverse surface of a block surface portion from which light is to be emitted, and an emission control device operable, when ambient illuminance is below a predetermined illuminance level, for automatically supplying the electric power stored in the electric double layer capacitor to the light emitting device to illuminate the light emitting surface of the light emitting device.
Such a light emitting block is applied to an attaching surface such as a side wall of a garage or a wall of a house. After application, sunlight passes through translucent regions of the block surface portion of the light emitting block, and strikes on the solar batteries. The solar batteries having received the sunlight generate electric power, and accumulate the electric power in the electric double layer capacitor at the same time.
When ambient illuminance falls below the predetermined illuminance level toward the evening, the emission control device automatically supplies the power stored in the double layer capacitor to the light emitting device, whereby the light emitting surface of the light emitting device begins to shine. The light emitted from the light emitting surface passes through the translucent regions of the block surface portion to radiate from the block to the ambient. In this way, the light emitting block performs a light emitting function.
That is, the light emitting block of this invention has an in-system power generating function provided by the solar batteries and electric double layer capacitor. All that is required is to lay the light emitting block in place. There is no need for a wiring operation or a subsequent checking operation. Moreover, there is no possibility of light emission stoppage in time of power failure due to a natural disaster or the like. The light emitting function is firmly maintained.
Thus, the light emitting block according to this invention has an appropriate in-system power generating function provided by the solar batteries and electric double layer capacitor. There is no need for a wiring operation or a subsequent checking operation, to realize improved workability and maintainability. Moreover, there is no possibility of light emission stoppage in time of unexpected power failure due to a natural disaster or the like, which provides improved response to emergency situations.
In the light emitting block of this invention, the light emitting device preferably comprises a planar light emitting device or a point light emitting device.
The light emitting device comprising a planar light emitting device as noted above is not too dazzling or offensive to view, which provides an improvement in design over the prior art. The light emitting device comprising a point light emitting device emits light farther than the planar light emitting device.
In the light emitting block of this invention, the planar light emitting device preferably has a transparent plate disposed parallel to the block surface portion, a light projecting device for injecting light from end surfaces of the transparent plate into the transparent plate along a direction of a plane thereof, a light scattering device with a surface of the transparent plate close to the block surface portion acting as a light scattering surface, and a light reflecting device with a surface of the transparent plate remote from the block surface portion acting as a light reflecting surface.
In time of light emission, the light injected by the light projecting device into the transparent plate along the direction of the plane thereof is reflected and deflected toward the block surface portion by the light reflecting surface on the reverse side. Then, the light, while being scattered by the light scattering surface on the front side, radiates to the ambient from the translucent regions of the block surface portion. Since a large part of incident light is released after the reflection from the light reflecting surface, the light emitting surface is bright. The light emitting surface gives a very mellow (soft) impression as a result of the light scattering action (light diffusion) of the light scattering surface.